Senate Democrats and a substantial number of Republicans believe they can save an obscure, 81 year-old U.S. government bank, despite almost united opposition from GOP leadership in both chambers of Congress, after a key test vote Wednesday showed that they have near-filibuster proof support.

One such advocate, Washington Democratic Sen. Maria Cantwell, pledged that it's not a question of if Congress will reauthorize the Export-Import Bank, but when.

"It will get done," she said in a news conference Thursday. "Someday."

That may be too late for the bank, a cause célèbre for conservatives who view the credit agency as a blatant example of crony capitalism, as its charter expires June 30. Ex-Im opponents have claimed the upper hand in negotiations, pointing out that there are few ways in which the supporters could force a vote by then, as nearly every member of the GOP leadership that controls the floor oppose the bank.

But the show vote in the Senate on Wednesday on an amendment to a defense bill proved the bank has widespread support—65 votes.

"Guess what's moving," said North Dakota Democratic Sen. Heidi Heitkamp. "The Ex-Im Bank and the support for the Ex-Im Bank. That's what's moving. We could do a standalone bill tomorrow."

"We've got 19 days and we can't pass a bill that has almost veto-proof support," she asked. "That is a bad statement on the United States Congress."

The bank's supporters, which include the U.S. Chamber of Commerce, claim that a historically noncontroversial issue has been taken over by right-wing, Koch brothers-backed ideologues. They see the bank as a deficit-reducing, economic booster that supports small U.S. businesses by guaranteeing loans to foreign buyers. They also note that dozens of other competing countries have similar export credit agencies.

But opponents point out that Ex-Im provides billions to its top beneficiary, the giant aerospace and defense firm Boeing, and that the Main Street advantages are overstated.

"I see Export-Import Bank as sort of a function of crony capitalism," said House Ways and Means Chairman Paul Ryan in a radio interview with Hugh Hewitt Wednesday. "It goes to the biggest of the Fortune 500 companies. It applies to 1 percent of our exports."

After proving their strong numbers, Ex-Im supporters now are searching for a real vote to extend its charter before it expires. Heitkamp said Wednesday that Senate Majority Leader Mitch McConnell promised Ex-Im supporters during the trade promotion authority talks that such a vote would happen.

"We're not done with this fight," she said. "The commitment that we received during the TPA debate was that we were going to have a meaningful, agreed upon vote in June."

But Don Stewart, a McConnell spokesperson, responded that the deal was a vote in June and "that happened."

"He did not pledge to hold multiple votes or guarantee any outcomes," he added. "But there's nothing stopping anyone from offering amendments to upcoming bills."

The best option for the bank's supporters appears to be attaching the vote to the major infrastructure package expected to move in July. While the charter would temporarily expire, House Republicans—many of whom oppose Ex-Im—would be forced to think twice before blocking a must-pass bill over a relatively minor issue.

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